Zipper tape



Dec. 18, 1962 o. FIRING 3,06

ZIPPER TAPE Filed July 18, 1960 fig. 1

INVENTOR Osborne Firing BY ATTORN EY United States Patentfififice3,068,908 i atented Dec. 18, 1962 3,668,908 ZIPPER TAPE Osborne Firing,Sherman Hill, Woodbury, Conn. Filed July 18, 196i), Ser. No. 43,526 4Claims. t'll. 139-384) My invention relates to tapes for zipperfasteners and more particularly to a woven tape in which a two-cordbeaded edge is formed during the weaving operation as an integral partof the tape.

While many attempts have been made to produce beaded edge tapes suitablefor zipper fasteners, it has heretofore not been possible to weave atape with such a beaded edge which would equal in quality a tape inwhich the cords are sewn to the tape in a separate operation. Usually,former methods of weaving a beaded edge tape have tied in the cord byweft threads passing over the cords. The result here is a verysubstantial loss in crosswise strength of the tape due to the greatpressure upon, and danger of rupture of, such weft threads by the jawsof the fastener elements. Another objection to prior tapes with twocords woven into one edge is that the position of the cords cannot bemaintained with suflicient accuracy to produce a good quality zipper.

One of the objects of my invention is to provide an improved tape forzipper fasteners in which the loss of crosswise strength by attachmentof the fastener elements is not only less than that encountered withother woven cord edge tapes, but also less than in tapes where the cordsare sewn to the tape in a separate operation, while at the same timeavoiding the extra cost involved in the sewing operation.

Another object is to provide an improved tape for zipper fasteners inwhich the cords are held firmly and accurately in proper position withrespect to the edge of the tape.

The tape of the present invention is adapted to be made on a needle loomas disclosed in my co-pending application, Serial Number 826,667, filedJuly 13, 1959. in a tape made as described in said patent, there are twopicks or weft threads laid between each change of the shed and thespecial warps or tie-in threads must necessarily cross the cords at asubstantial angle since while crossing the cords, they must passlengthwise of the tape over two such picks or weft threads and then, onthe next subsequent crossing back over the cords, the angle of eachspecial Warp is inthe opposite direction. There is, thus, a tendency forthat portion of the cord between the crossings or tie loops to shiftlaterally of the tape since each special warp or tie-in thread (which isunder tension) will tend to pull the cord into a right anglerelationship with it. This has a tendency to produce a snaky effect onthe cords and with a tape manufactured according to the aforesaidapplication, the cord on one side of the tape will tend to shiftlaterally in one direction at the same place where the cord on theopposite side will tend to shift in the opposite direction. This resultsin a situation where the cords will not be exactly opposite one anotherwith the result that the zipper fastener elements cannot properly grasparound the cords.

A specific object of my invention, therefore, is to eliminate thedifficulty caused by such non-parallelism of the cords so that thezipper fastener elements will always grasp around the cords properly.

Another object of my invention is to provide an improved tape for zipperfasteners wherein the cord tie-in threads are so engaged with the weftthreads that the tendency for such weft threads to pull out of the planeof. the fabric is reduced to a minimum. Thus, none of the weft threadsare placed under extra tension so that the crosswise strength of thezipper stringer is substantially the full crosswise strength of the bodyof the tape.

Other objects and advantages of my invention will hereinafter more fullyappear.

In the accompanying drawings, I have shown for the purpose ofillustration, one embodiment which my invention may assume in practice.In the drawings:

FIG. 1 is a plan view of my improved zipper tape;

PEG. 2 is also a plan view on an enlarged scale with the weave opened upto show the tape construction;

PEG. 3 is a cross-section with the weave opened up taken along line 3-3of FIG. 2;

FIG. 4 is a cross-section on line 4-- 4 of FIG. 2 on an enlarged scaleindicating how the fastener'elements are applied to the tape; and,

FIG. 5 is a small section to indicate a condition abovereferred to whichresults in prior tapes made with a loom as described in the aforesaidapplication.

The web or fiat portion 5 of the tape is preferably of the twill orherring-bone type of weave commonly used in zipper fasteners. It is madeup of warp threads 6 and weft threads 7. Each warp thread goes under 4and over 4 and the next adjacent warp thread steps two Weft threadsalong the length of the tape to make the familiar twill pattern. Theweave illustrated is' adapted to be made on a needle loom whichnecessarily lays two picks or weft threads between each shift of theshed. Such a tape has along one edge a knitted selvage but in thedrawings, this is not shown because only a portion of the width of thetape appears. The weft thread 7 in FIG. 4 is shown broken between thecords because the weave of the fiat portion of the tape is shown openas. in FIG. 2.

The beaded edge is formed essentially by two relatively largecords C andC one cord being disposed on each side of the tape. These cords are heldin place by special warp threads and in the embodiment illustrated, cordC is held by its special warp thread W and cord C is held by its specialWarp thread W At every certain multiple of double picks of the weft,

the special warp W is brought from under the previous pair of picks,here designated P diagonally across the top of cord C jumping over atleast one pair of picks and under the next pair labeled P being returnedback across cord C diagonally while jumping at least another pair ofpicks and under the pair of picks P which follows.

At the same time, the special warp W starting from the same position isbrought from over the same previous pair of picks P diagonall across thebottom of cord C over said same next pair of picks P diagonally backunder cord C and over the following pair of picks P It will thus beseenthat the special warps are interengaged with the same weft threadsat su bstantiallythe, same place on one side of the cords, each suchwarp crossing its cord diagonally at the same angle with respect to thecords and then being interengaged with identical weft threads on theother side of the cord, and then re-crossing their respective cordsagain in the same direction and repeating. Thus, the cord tie loops arelyin susbtantially in common planes vertically of the tape.

Since the cord tie loops cross at substantial angles and each succeedingloop is at the angle opposite to a preceding loop, each of the cordswill tend to assume a slightly snaky effect. This is indicated in P16. 1where every other portion of the cord between the tie loops, heredesignated 8, tends to bulge slightly inwardly while the portions 9 inbetween tend to bulge slightly outwardly. However, with my improvedtape, as can be seen in FIG. 3,

any such tendency for the cords to shift slightly out of line is thesame for one cord as the other; in other words, the cords will always beparallel. However, with other attempts to weave in cords by specialthreads crossing at an angle, the angle at any place on one cord wasusually opposite to that for the other cord with the result that thecords at any given place would not be exactly opposite one another. Thisis shown on an exaggerated scale in FIG. 5 where the top cord 1% mayshift outwardly while the bottom cord 11 may shift inwardly. Thisresults in a situation where a fastener element 12 having jaws 13 cannotgrip symmetrically on the cords with the result that a poor zipper isobtained. Any slight snaky effect resulting from my construction is notobjectionable because the cords are always parallel and will be receivedby the jaws symmetrically.

These special warps need not be of the same material or size as theregular warps; for example, they may be of more tightly twisted cottonor nylon to provide extra strength to the cord tie loops.

It will also be noted that at the places Where one of the special warpsis pulling on a pair of picks, the other special warp is pulling on thesame pair of picks at substantially the same place and in the oppositedirection, thus balancing the forces and minimizing the tendency forthese picks to be placed under extra tension. While for purpose ofillustration, in FIGS. 2 and 4 these warps appear to be separated, itwill be understood that in the actual weave, they will be lying tightlytogether and thus crossing the picks at substantially the same place.

While the cord tie loops are spaced apart, preferably a distance of atleast four picks, they nevertheless tend to imbed themselves in thecords so as not to vary the overall dimension of the cord edge. Thus itis possible to control the size of the corded edge much more accuratelythan in the case where the cords are woven in by threads crossing ateach shift of the shed so as to form a tube around the cord.

At the outer edge of the tape, there are maybe two additional warpthreads 14 and 15 which are preferably interwoven with the picks over 2under 2 so as to afford a firm anchoring edge. The edge does not projectbeyond the cords as much as would appear in FIGS. 2 and 4 in which theweave is expanded for purpose of illustration.

It may be noted here that the space between the cords is devoid of anywarp threads so that the wefts do not have to cross each other at such asharp angle as in the main body of the fabric. This has the advantagethat the pressure exerted by the clamping jaws 1'3 of the fastenerelements do not have a tendency to crush or weaken the fibers of theweft threads.

It will thus be seen that in all respects, the fastener tape is of suchconstruction and the cords are so arranged and held that the crosswisestrength of the fabric tape is not diminished to any appreciable extentby the attachment of the fastener elements.

What I claim is:

1. A tape for zippers comprising a woven web having a beaded edge, thebeaded edge being formed by two relatively large cords disposed on eachside of the tape and being held in place each by its own special warpthread, such special warps being interengaged with the same weft threadsat substantially the same place on one side of the cords, each specialwarp crossing its cord diagonally at the same angle with respect to thecords, said warps then being interengaged with other weft threads againat the same place then re-crossing their respective cord diagonally andrepeating the crossings forming tie loops which lie in substantiallycommon planes vertically of the tape.

2. A tape for zippers comprising a woven web having a beaded edge, thebeaded edge being formed by two relatively large cords disposed on eachside of the tape and being held in place each by its own special warpthread, one of said special warps being engaged under selected pairs ofpicks first on one side of its cord then on the other, the other of saidspecial warps being engaged over the same selected pairs of picks and atsubstantially the same place as said one special warp, whereby the pullagainst such picks of one special warp is substantially balanced by thepull of said other special warp.

3. A tape for zippers comprising a woven web having a beaded edge, thebeaded edge being formed by two relatively large cords disposed onopposite sides of the tape and being held in place by special warpthreads, one of said special warp threads first crossing under a firstpair of wefts then angularly over a top cord, then under the third pairof weft threads angularly again over the top cord and under the fifthpair of weft threads and repeating, the other of said special warpthreads passing first over said first pair of weft threads at the sameside of the cords as said first special warp thread, then angularlyunder the bottom cord and second pair of weft threads, then over thethird pair of weft threads and angularly across the bottom cord andrepeating, the two warp threads throughout their extent beingsubstantially in alignment as viewed from the top of the tape.

4. A tape for zippers comprising a woven web having a beaded edge, thebeaded edge being formed by two relatively large cords disposed on eachside of the tape and being held in place each by its own special warpthread, wherein at every certain multiple of double picks of the weft,one special warp is brought from under the previous pair of picks,diagonally across the top of its cord jumping over at least one pair ofpicks and under the next pair, being returned back across its corddiagonally while jumping at least another pair of picks and under thepair of picks which follows, while at the same time, the other specialwarp starting from the same position is brought from over the sameprevious pair of picks diagonally across the bottom of the said othercord and over the following pair of picks.

References Cited in the file of this patent UNITED STATES PATENTS

